Penegra dilates the arteries in the male reproductive organ and thus allows filling of blood into sinusoids (small spaces in the male reproductive organ). This hardens the reproductive organ in men;the veins are then compressed restricting the blood flow out of it. This filling of blood into the male reproductive system causes the stiffening of male organ for reproduction. It acts as the inhibitor of the enzyme PDE-5 that is the reason for the reduction of the blood supply to the man's organ for reproduction during the love-making activity. It promotes the activity of the enzyme cGMP that supports in increasing the blood supply to the male reproductive system. Thus, the desired hard on is attained during the love-making activity are attained by the impotent men. As male organ for reproduction gets stiff the arteries and veins in it get stiff and robust that leads to the reduction in the blood supply out of it. This way, men are able to hold the stiffness of manhood for long time with the help of penegra 100mg tablets.